Tetrax Organ

The Tetrax
Organ follows a lineage of electronic musical instruments based on
touch. It was redesigned once, as Tetrazzi. It has four wooden bars that
you press to express four oscillators within. Each oscillator has
its own fine tuning slider, embedded right within its bar. Also,
there is are two master pitch knobs, and two master chaos knobs.
Each master chaos knob makes the instrument go from pure sawtooth
tones to a nest of noise. It does this by gradually increasing
modulation from one oscillator to the next in a circular pattern.
The reason there are two of each knobs: the Tetrax is all about
timbre modulation, by changing the upslope and downslope of
triangle waves separately. So, for master pitch and chaos, there
is a separate upwards and downwards knob. In general, Tetrax is
for funky bass and complex tones, while Sidrax is for sweet melodies. Of course
they all have noise available at any point!

There are 28 modulation points brought forth as banana jacks. They
are arranged in four columns, representing the four bars. Their
layout is shifted diagonally, to allow inputs in proximity to
outputs. This is for touch-playability; you can make banana jack
metal studs that can be squished by hand to gesture-patch the
instrument. Inputs are cool colors: blue, green, and grey. Outputs
are hot colors: red and orange. The grey jacks are parallel inputs
with the master knobs: the two on the left are for master pitch,
the right two are master chaos. The color allotment for each bar
is as follows:

Two orange jacks, representing the press and release gestures
on that bar in voltage.

One red jack, which is the pure triangle output of that
oscillator.

Two green jacks, that are "glitch" inputs. They cause the
boundary conditions of each oscillator to wire to the output of
another. A modulation inspired by circuit bending.

One blue jack, an fm modulation input for that
oscillator.

The Tetrax organ has a stereo-mini output on the back. This
is because each bar, outputs in different channels during the
press/release cycle. In addition to the stereo-mini jack, it has
an power switch, and optional built-in batteries, or an external,
9volt battery snap.